Are parties domocratizing themselves? the evolution of leardership selection in Spain (1977-2008)

The aim of this paper is to verify, for the Spanish case, whether between 1977 and 2008 has increased the internal democracy of the major political parties (PSOE, AP / PP, PCE / IU, PNV and CDC). To do this, we will focus on their leadership selection processes, one of the key elements associated with intra-party democracy. The paper is going to introduce data on four different dimensions of leadership selection: the certification process, the voting procedure, the inclusiveness of the selectorate and, finally, the degree of competitiveness. The results will show that have been few changes in the leadership selection processes of the Spanish political parties since 1977. However, the results of the Spanish case will also be used to suggest some preliminary links between the four dimensions.

The Evolution of the Climate Change Regime: Beyond a North-South Divide?

This research primarily analyses relevant climate bargaining dynamics that have been informed by a North-South impasse. This working paper argues that the first stage of negotiations for a climate convention indeed witnessed a North-South divide which became institutionalized in the Framework Convention on Climate Change. However, in subsequent negotiation rounds the key loci of bargaining struggles was centered between developed countries, in which relevant North-South cooperation dynamics were also present. Finally, this paper assesses the unfinished post-Kyoto bargaining process in which two trends are already being observed: both the emergence of a new geopolitics between the United States and major developing countries, and a fragmentation process within the South, in which the Copenhagen Accord itself has begun to institutionalize such fragmentation.

Triassic stratigraphic evolution of the Arabian-Greater India embayment of the southern Tethys margin

An exceptional, tectonically remarkably unaffected, nearly 200 m-thick continuous section of hemipelagic and turbiditic sediments, covering most of the Triassic is described from the Batain Complex of north-eastern Oman. According to conodont and radiolarian data the sequence spans the late Scythian to the early Norian, a time period of nearly 30 M. Coupled with a high resolution stratigraphy, the lithostratigraphy, sedimentology, as well as sequence and isotope stratigraphy of the section are documented. For the Triassic of the Batain Plain we propose the new name Sal Formation, which replaces the formerly used Matbat Formation, and subdivide it into three new members. The Sal Formation was deposited on the proximal continental margin of northeastern Arabia and records various depositional environments. The lower member is interpreted as the distal part of a homoclinal ramp which evolves to a distally steepened ramp during time of deposition of the middle member. The upper member displays a toe of slope position which is indicated by an increase of proximal turbidites. These sediments form part of a segment of the Neo-Tethyan embayment between Arabia and India. The stratigraphic analysis indicates highly varying sedimentation rates from a minimum of 2 m/M gamma around the Anisian/Ladinian boundary up to 15 m/M gamma during the Lower and Upper Triassic. Sequence-stratigraphically, the Sal section is subdivided into six third order cycles which are biochronologically well integrated into the global Triassic cycle chart. The mixed siliciclastic-calcareous upper member of the Sal Formation typically shows highstand related carbonate shedding. It is, therefore, an important test case for sequence-stratigraphic controlled carbonate export to mixed basin fills. The well developed sequence stratigraphic cycles are mirrored in the isotope patterns. Additionally, the carbon and oxygen isotope data from the Sal Formation record the same chemostratigraphic marker at the Spathian/Anisian boundary known from other Tethyan sections.

The Evolution of Trypanosomes Infecting Humans and Primates

Based on phylogenetic analysis of 18S rRNA sequences and clade taxon composition, this paper adopts a biogeographical approach to understanding the evolutionary relationships of the human and primate infective trypanosomes, Trypanosoma cruzi, T. brucei, T. rangeli and T. cyclops. Results indicate that these parasites have divergent origins and fundamentally different patterns of evolution. T. cruzi is placed in a clade with T. rangeli and trypanosomes specific to bats and a kangaroo. The predominantly South American and Australian origins of parasites within this clade suggest an ancient southern super-continent origin for ancestral T. cruzi, possibly in marsupials. T. brucei clusters exclusively with mammalian, salivarian trypanosomes of African origin, suggesting an evolutionary history confined to Africa, while T. cyclops, from an Asian primate appears to have evolved separately and is placed in a clade with T. (Megatrypanum) species. Relating clade taxon composition to palaeogeographic evidence, the divergence of T. brucei and T. cruzi can be dated to the mid-Cretaceous, around 100 million years before present, following the separation of Africa, South America and Euramerica. Such an estimate of divergence time is considerably more recent than those of most previous studies based on molecular clock methods. Perhaps significantly, Salivarian trypanosomes appear, from these data, to be evolving several times faster than Schizotrypanum species, a factor which may have contributed to previous anomalous estimates of divergence times.

How life history and demography promote or inhibit the evolution of helping behaviours.

In natural populations, dispersal tends to be limited so that individuals are in local competition with their neighbours. As a consequence, most behaviours tend to have a social component, e.g. they can be selfish, spiteful, cooperative or altruistic as usually considered in social evolutionary theory. How social behaviours translate into fitness costs and benefits depends considerably on life-history features, as well as on local demographic and ecological conditions. Over the last four decades, evolutionists have been able to explore many of the consequences of these factors for the evolution of social behaviours. In this paper, we first recall the main theoretical concepts required to understand social evolution. We then discuss how life history, demography and ecology promote or inhibit the evolution of helping behaviours, but the arguments developed for helping can be extended to essentially any social trait. The analysis suggests that, on a theoretical level, it is possible to contrast three critical benefit-to-cost ratios beyond which costly helping is selected for (three quantitative rules for the evolution of altruism). But comparison between theoretical results and empirical data has always been difficult in the literature, partly because of the perennial question of the scale at which relatedness should be measured under localized dispersal. We then provide three answers to this question.

Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery

Three different periods may be considered in the evolution of knowledge about the clinical and epidemiological aspects of Chagas disease since its discovery: (a) early period concerning the studies carried out by Carlos Chagas in Lassance with the collaboration of other investigators of the Manguinhos School. At that time the disease was described and the parasite, transmitters and reservoirs were studied. The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disease; (b) second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American countries. Particularly important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of the Romaña sign in the 1930 decade, facilitating the diagnosis of the early phase of the disease. However, the chronic phase, which was the most important, continued to be difficult to recognize; (c) period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies conducted by Laranja, Dias and Nóbrega in Bambuí updated the description of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on, the disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d) period of enlargement of knowledges on the disease. The studies on denervation conducted in Ribeirão Preto by Fritz Köberle starting in the 1950 decade led to a better understanding of the relations between Chagas disease and megaesophagus and other visceral megas detected in endemic areas.

Chemical and carbon isotopic evolution of hydrocarbons during prograde metamorphism from 100°C to 550°C: Case study in the Liassic black shale formation of Central Swiss Alps

Hydrocarbon distributions and stable isotope ratios of carbonates (delta(13)C(car), delta(18)O(car)), kerogen (delta(13)C(ker)), extractable organic matter (delta(13)C(EOM)) and individual hydrocarbons of Liassic black shale samples from a prograde metamorphic sequence in the Swiss Alps were used to identify the major organic reactions with increasing metamorphic grade. The studied samples range from the diagenetic zone (< 100 degrees C) to amphibolite facies (similar to 550 degrees C). The samples within the diagenetic zones (< 100 and 150 degrees C) are characterized by the dominance of C-< 20 n-alkanes, suggesting an origin related with marine and/or bacterial inputs. The metamorphic samples (200 to 550 degrees C) have distributions significantly dominated by C-12 and C-13 n-alkanes, C-14, C-16 and C-18 n-alkylcyclopentanes and to a lesser extend C-15, C-17 and C-21 n-alkylcyclohexanes. The progressive C-13-enrichment (up to 3.9 parts per thousand) with metamorphism of the C-> 17 n-alkanes suggests the occurrence of cracking reactions of high molecular weight compounds. The isotopically heavier (up to 5.6 parts per thousand) C-< 17 n-alkanes in metamorphic samples are likely originated by thermal degradation of long-chain homologous with preferential release of isotopically light C-1 and C-2 radicals. The dominance of specific even C-number n-alkylcyclopentanes suggests an origin related to direct cyclization mechanism (without decarboxylation step) of algal or bacterial fatty acids occurring in reducing aqueous metamorphic fluid conditions. The regular increase of the concentrations of n-alkylcycloalkanes vs. C-> 13 n-alkanes with metamorphism suggests progressive thermal release of kerogen-linked fatty acid precursors and degradation of n-alkanes. Changes of the steroid and terpenoid distributions are clearly related to increasing metamorphic temperatures. The absence of 18 alpha(H)-22,29,30-trisnorneohopane (Ts), the occurrence of 17 beta(H)-trisnorhopane, 17 beta(H), 21 alpha(H)-hopanes in the C-29 to C-31 range and 5 alpha(H),14 alpha(H),17 alpha(H)-20R C-27, C-29 steranes in the low diagenetic samples (< 100 degrees C) are characteristic of immature bitumens. The higher thermal stress within the upper diagenetic zone (150 degrees C) is marked by the presence of Ts, the disappearance of 17 beta(H)-trisnorhopane and thermodynamic equilibrium of the 22S/(22S + 22R) homohopane ratios. The increase of the alpha alpha alpha-sterane 20S/(20S + 20R) and 20R beta beta/(beta beta + alpha alpha) ratios (from 0.0 to 0.55 and from 0.0 to 0.40, respectively) in the upper diagenetic zone indicates the occurrence of isomerization reactions already at < 150 degrees C. However, the isomerization at C-20 (R -> S) reaches thermodynamic equilibrium values already at the upper diagenesis (similar to 150 degrees C) whereas the epimerisation at C-14 and C-17 (alpha alpha ->beta beta) arrives to constant values in the lower anchizone (similar to 200 degrees C). The ratios Ts vs. 17 alpha(H)-22,29,30-trisnorneohopane [(Ts/(Ts + Tm)] and 18 alpha(H)-30-norneohopane (C29Ts) vs. 17 alpha(H),21 beta(H)-30-norhopane [C29Ts/(C29Ts + C-29)] increase until the medium anchizone (200 to 250 degrees C) from 0.0 to 0.96 and from 0.0 to 0.44, respectively. An opposite trend owards lower values is observed in the higher metamorphic samples. The occurrence of specific hydrocarbons (e.g., n-alkylcyclopentanes, cadalene, hydrogenated aromatic compounds) in metamorphic samples points to kerogen degradation reactions most probably occurring in the presence of water and under reducing conditions. The changes of hydrocarbon distributions and carbon isotopic compositions of n-alkanes related to metamorphism suggest that the organic geochemistry may help to evaluate the lowest grades of prograde metamorphism. Copyright (c) 2005 Elsevier Ltd.

The ecotopes and evolution of triatomine bugs (triatominae) and their associated trypanosomes

Triatomine bug species such as Microtriatoma trinidadensis, Eratyrus mucronatus, Belminus herreri, Panstrongylus lignarius, and Triatoma tibiamaculata are exquisitely adapted to specialist niches. This suggests a long evolutionary history, as well as the recent dramatic spread a few eclectic, domiciliated triatomine species. Virtually all species of the genus Rhodnius are primarily associated with palms. The genus Panstrongylus is predominantly associated with burrows and tree cavities and the genus Triatoma with terrestrial rocky habitats or rodent burrows. Two major sub-divisions have been defined within the species Trypanosoma cruzi, as T. cruzi 1 (Z1) and T. cruzi 2 (Z2). The affinities of a third group (Z3) are uncertain. Host and habitat associations lead us to propose that T. cruzi 1 (Z1) has evolved in an arboreal, palm tree habitat with the triatomine tribe Rhodniini, in association with the opossum Didelphis. Similarly we propose that T. cruzi (Z2) and Z3 evolved in a terrestrial habitat in burrows and in rocky locations with the triatomine tribe Triatomini, in association with edentates, and/or possibly ground dwelling marsupials. Both sub-divisions of T. cruzi may have been contemporary in South America up to 65 million years ago. Alternatively, T. cruzi 2 (Z2) may have evolved more recently from T. cruzi 1 (Z1) by host transfers into rodents, edentates, and primates. We have constructed a molecular phylogeny of haematophagous vectors, including triatomine bugs, which suggests that faecal transmission of trypanosomes may be the ancestral route. A molecular clock phylogeny suggests that Rhodnius and Triatoma diverged before the arrival, about 40 million years ago, of bats and rodents into South America.

Nuclear rDNA-based molecular clock of the evolution of triatominae (Hemiptera: Reduviidae), vectors of Chagas disease

The evolutionary history and times of divergence of triatomine bug lineages are estimated from molecular clocks inferred from nucleotide sequences of the small subunit SSU (18S) and the second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA of these reduviids. The 18S rDNA molecular clock rate in Triatominae, and Prosorrhynchan Hemiptera in general, appears to be of 1.8% per 100 million years (my). The ITS-2 molecular clock rate in Triatominae is estimated to be around 0.4-1% per 1 my, indicating that ITS-2 evolves 23-55 times faster than 18S rDNA. Inferred chronological data about the evolution of Triatominae fit well with current hypotheses on their evolutionary histories, but suggest reconsideration of the current taxonomy of North American species complexes.

Speculations on the origin and evolution of the genus Leishmania

Recently two hypotheses have been proposed for the evolution of Leishmania involving respectively a Neotropical or Paleartic origin for the species. Here an alternative proposal on the phylogeny of Leishmania based on the major divisions within the genus is presented. In this hypothesis a Neotropic origin is retained for L. (Viannia) and Paraleishmania, a recently desribed section within the genus Leishmania, while an African origin is proposed for L. (Leishmania) and possibly Sauroleishmania. The current distribution of Leishmania in the Neotropics is explained as the product of multiple introductions of Leishmania parasites into the New World. Problems with organismal identity in Sauroleishmania and the use of molecular sequence data in inferring phylogenies are also discussed.

Phylogeny of the kinetoplastida: taxonomic problems and insights into the evolution of parasitism

To further investigate phylogeny of kinetoplastid protozoa, the sequences of small subunit (18S) ribosomal RNA of nine bodonid isolates and ten isolates of insect trypanosomatids have been determined. The root of the kinetoplastid tree was attached to the branch of Bodo designis and/or Cruzella marina. The suborder Trypanosomatina appeared as a monophyletic group, while the suborder Bodonina was paraphyletic. Among bodonid lineages, parasitic organisms were intermingled with free-living ones, implying multiple transitions to parasitism and supporting the `vertebrate-first hypothesis'. The tree indicated that the genera Cryptobia and Bodo are artificial taxa. Separation of fish cryptobias and Trypanoplasma borreli as different genera was not supported. In trypanosomatids, the genera Leptomonas and Blastocrithidia were polyphyletic, similar to the genera Herpetomonas and Crithidia and in contrast to the monophyletic genera Trypanosoma and Phytomonas. This analysis has shown that the morphological classification of kinetoplastids does not in general reflect their genetic affinities and needs a revision.